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Topic: Science News Roundup (Read 6110 times)

About 80 light-years away, an enormous, dusty ring swirls around a sunlike star, with a defined inner edge that is probably sculpted by a planet orbiting at 140 times Earth’s distance from the sun.

A planet located so far from a sunlike star presents an astronomical conundrum.

“How do you get a planet out that far? We don’t know how to form something out there,” astronomer Karl Stapelfeldt of NASA’s Goddard Space Flight Center in Greenbelt, Md., said on June 14 at the 220th Meeting of the American Astronomical Society.

Stapelfeldt and a team led by John Krist of the Jet Propulsion Laboratory in Pasadena, Calif., used the Hubble Space Telescope to study 10 stars suspected of hosting large debris disks. Hubble saw a ring around only one, HD 202862, which resides near the southern constellations Grus and Microscopium.

Everything about the dusty circle — the biggest ever observed around a solar cousin — is huge. In places, the ring itself is 70 times wider than the Earth-sun distance, called an astronomical unit. From end to end, the debris disk is roughly 400 astronomical units long — larger than the well-known ring surrounding the star Fomalhaut. Like that ring, the newly observed one is also groomed by a celestial gardener — the planet lives about 140 astronomical units from HD 202862.

Baby bluebirds don’t survive as well near rumbling traffic and other human din as they do amid natural lullabies.

In a Virginia study, 35 percent more chicks died in the noisiest nests than in the most remote ones. Researchers found that chicks didn’t adjust for the noise by begging louder or at different frequencies. So parents may not have gotten the right cues for nestling care, behavioral ecologist John Swaddle suggested June 12 at the annual meeting of the Animal Behavior Society.

Until recently, most research on how human-made noise discombobulates birds has focused on how adults adjust their songs (or don’t) or on what species will nest at all among the din. Research is now turning to how noise might directly affect the success of a species. One earlier study on reproductive success, in common European birds called great tits, found smaller clutches near roaring highways.

Clutch size didn’t shrink among eastern bluebirds (Sialia sialis), said Swaddle, a professor at the College of William and Mary in Williamsburg, Va. Birds settling in to the 43 nest boxes he and his colleagues monitored for two years all started with about the same number of eggs.

Just what made noisier nests less successful after hatching isn’t clear, but Swaddle suspects that noise kept parents from caring for their nestlings properly. Noise might have made food harder to find, or it might have masked normal parent-chick chat. Even though baby birds have become an icon of endlessly demanding maws, parents do tune their feeding effort to begging calls, and research has confirmed the importance of communication.

Microphones set up 15 meters from nest boxes revealed that local human clamor could mask part of the nestlings’ peeps. Adult birds often perch at a similar distance from their nests when checking out the local situation.

In what seems like a blow for humanity, a very smart chimpanzee in Japan crushes any human challenger at a number memory game.

After the numbers 1 through 9 make a split-second appearance on a computer screen, the chimp, Ayumu, gets to work. His bulky index finger flies gracefully across the screen, tapping white squares where the numbers had appeared, in order. So far, no human has topped him.

Ayumu’s talent caused a stir when researchers first reported it in 2007 (SN: 12/8/2007, p. 355). Since then, the chimp’s feat has grown legendary, even earning him a starring role in a recent BBC documentary.

But psychologist Nicholas Humphrey says the hype may be overblown. In an upcoming Trends in Cognitive Sciences essay, Humphrey floats a different explanation for Ayumu’s superlative performance, one that leaves humans’ memory skills unimpugned: Ayumu might have a curious brain condition that allows him to see numbers in colors. If Humphrey’s wild idea is right, the chimpanzee’s feat has nothing to do with memory.

“When you get extraordinary results, you need to look for extraordinary ideas to explain them,” says Humphrey, of Darwin College at Cambridge University in England.

The idea came to him after listening to two presentations at a consciousness conference in 2011. Tetsuro Matsuzawa of the Primate Research Institute at Kyoto University in Japan described his research on the memory skills of Ayumu, his mother Ai, and two other mom-offspring pairs. And neuroscientist David Eagleman of Baylor College of Medicine in Houston talked about the brain condition known as synesthesia, which causes people to attach sensory experiences to letters or numbers. A synesthete might always see the number four as blue, for instance.

Because synesthesia usually applies to strings of symbols such as letters or numbers, there was no reason to think that animals other than humans would experience it. No reason, that is, until Ayumu and his chimp colleagues learned numbers, Humphrey says.

If Ayumu does perceive the numbers on the screen in colors, then when the digits disappear each white square that replaces them would, in his mind, have a distinct aftereffect color. Ayumu could simply be ordering these colors in a learned sequence without having to remember the original numbers, Humphrey proposes.

One of the biggest mysteries in volcanology may finally have a solution. An eruption long thought to have gone off in the year 1258, spreading cooling sulfur particles around the globe, happened the year before in Indonesia, scientists report.

Until now, researchers have known a big volcano went off somewhere in the world around that time, but they didn’t know exactly where or when.

The new report still remains something of a mystery. Franck Lavigne, a geoscientist at Panthéon-Sorbonne University's Laboratory of Physical Geography in Meudon, France, showed data and close-up photographs of the remains of the perpetrator volcano on June 14 at an American Geophysical Union conference on volcanism and the atmosphere. But he declined to name the specific volcano, saying he had agreed with his international colleagues not to identify it until the work is published in a peer-reviewed journal.

“We have new and solid evidence for the biggest volcanic eruption in 7,000 years,” Lavigne said.

Consensus in the meeting hallways was that he showed pictures of Indonesia. Lavigne would say only that Indonesia has more than 130 active volcanoes.

Scientists know a big eruption must have happened in the mid-13th century because ice cores from Greenland and Antarctica dating to that time contain huge amounts of sulfur. Tree rings, historical records and other evidence also show that the planet cooled soon thereafter. Big volcanic eruptions can spew sulfur particles into the upper atmosphere, where they spread around the globe and reflect sunlight, temporarily chilling the planet.

Leading candidates for the 1258 eruption have included Mexico’s El Chichón, which also erupted in 1982, and Quilotoa in the Ecuadorean Andes. But the chemical composition of rocks from those volcanoes, among other factors, don’t really match the 1258 sulfur from ice cores.

Red disks, hand stencils and club-shaped drawings lining the walls of several Stone Age caves in Spain were painted so long ago that Neandertals might have been their makers, say researchers armed with a high-powered method for dating ancient stone.

Scientists have struggled for more than a century to determine the ages of Europe’s striking Stone Age cave paintings. A new rock-dating technique, which uses bits of mineralized stone to estimate minimum and maximum ages of ancient paintings, finds that European cave art started earlier than researchers have assumed — at least 40,800 years ago, say archaeologist Alistair Pike of the University of Bristol in England and his colleagues.

Pike’s team presents its findings in the June 15 Science.

Previous age estimates were based on stylistic comparisons of drawings in different caves and radiocarbon dates for ancient pigments containing charcoal or other organic material. That research indicated that people began creating cave paintings in Europe possibly 36,000 years ago. Some researchers suspect that Homo sapiens made rapid advances in symbolic thinking around that time.

New evidence of European cave art’s early origin fits a scenario in which wall drawings and other symbolic behaviors extend far back in the Stone Age (SN: 8/13/11, p. 22). People may have begun cave painting either before or shortly after entering Europe as early as 45,000 years ago (SN Online: 11/2/11), Pike suggests. Or perhaps Neandertals that already inhabited Europe drew on cave walls before their evolutionary cousins arrived, he says.

“If cave painting started before the arrival of modern humans, it would mean that hand stencils on cave walls are outlines of Neandertals’ hands,” Pike says. “We will need to date more examples to see if this is the case.”

Neandertals died out around 30,000 years ago. Many cave paintings in the new study date to no more than 21,000 years ago, clearly marking them as creations of H. sapiens.

Only small pigment scrapings have been radiocarbon dated to reduce damage to Stone Age artworks. Such tiny samples magnify the distorting effects of contamination on radiocarbon age estimates. Scientists also can’t be sure that charcoal in ancient pigments isn’t considerably older than the rock art being dated.

For the new study, Pike’s team employed a technique called uranium-series dating to analyze thin mineral deposits that had formed over or under parts of 50 paintings and engravings in 11 Spanish caves. Uranium incorporated into the minerals at the time of formation decays into a form of radioactive thorium at a known rate, allowing researchers to calculate its age.

“Neandertals were capable of producing cave art, and these new dates make it probable that cave art does go back to the Neandertal period,” Bahn holds.

Data from Pike’s team show that cave art in Europe was created over a longer period than previously assumed, comments archaeologist Daniel Richter of the University of Bayreuth, Germany, a specialist in dating methods. Richter suspects that modern humans crafted these earliest cave paintings, because no evidence exists that Neandertals were involved.

Two dating studies at a German cave, one led by Richter and another by archaeologist Thomas Higham of the University of Oxford in England, place painted shapes, bone figurines and other artifacts often associated with modern humans at about 42,500 years ago. Those studies employed radiocarbon dating and a method to estimate the time since artifacts were exposed to a Stone Age fire, but not uranium-series dating.

“I think it is far more likely that all of the art at European sites was made by modern humans, although it’s possible that a Neandertal hand was involved,” Higham says.

Terrified insects can haunt their homeland after they die. Chemical remnants of fear in the rotting corpses of grasshoppers slow the decomposition of dead grass and other debris important for fertilizing new plant growth, a new study finds.

Spiders that frighten grasshoppers may thus play an unrecognized role in shaping ecosystems, adding a menacing presence that both cows the predators’ prey and suppresses the local vegetation, researchers report in the June 15 Science.

New clues in a mass murder that took place 252 million years ago points to a suspect: Ocean acidification may have driven the largest extinction of animals the world has ever seen.

Carbon dioxide belched out by volcanic eruptions during the Permian period could have caused the oceans’ chemistry to change. That’s worrisome because CO2 levels are rising today — thanks to the burning of fossil fuels — and pushing down seawater pH, researchers report online June 8 in Geology.

“The worst biodiversity catastrophe we've had in the history of animal life appears to have been associated with ocean acidification and other kinds of environmental changes we anticipate in the coming centuries,” says Jonathan Payne, a paleobiologist at Stanford University. “It’s a useful comparison point to have in mind as we think about the future of the modern oceans.”

The Great Dying at the end of the Permian period 252 million years ago wiped out most animal species, with marine critters hit hardest. Popular explanations include an upwelling of deep, oxygen-poor waters that suffocated life near the surface, or perhaps huge eruptions in Siberia that warmed and acidified oceans.

To distinguish between those scenarios, Payne and colleagues examined minerals in marine sediments and in fossilized, toothlike parts from prehistoric creatures that looked like eels. The minerals, made from calcium that had once been dissolved in seawater, had higher proportions of a lighter form of the element after about 250 million years ago, the researchers found.

A world warmed by volcanic eruptions would have increased levels of this light calcium isotope, the researchers’ simulations suggest. More intense rains would have flushed calcium into the ocean by eroding rocks on land, which tend to be made of the light calcium. Seawater that soaked up carbon dioxide and became more acidic would have stunted the productivity of organisms that pull calcium out of the water, allowing it to build up in the ocean.

Other lines of evidence corroborate this story. Previous studies have found that not only calcium but also carbon tends to get lighter in limestone that was formed after the extinction, a shift that could also be explained by more erosion on land. And acidified oceans would have made life particularly difficult for thick-shelled creatures, which died out in droves during the extinction.

By baffling the brain, saccharin and other sugar-free sweeteners — key weapons in the war on obesity — may paradoxically foster overeating.

At some level, the brain can sense a difference between sugar and no-calorie sweeteners, several studies have demonstrated. Using brain imaging, San Diego researchers now show that the brain processes sweet flavors differently depending on whether a person regularly consumes diet soft drinks.

“This idea that there could be fundamental differences in how people respond to sweet tastes based on their experience with diet sodas is not something that has gotten much attention,” says Susan Swithers of Purdue University in West Lafayette, Ind. A key finding, she says: Brains of diet soda drinkers “don’t differentiate very well between sucrose and saccharin.”

Erin Green and Claire Murphy of the University of California, San Diego and San Diego State University recruited 24 healthy young adults for a battery of brain imaging tests. Half reported regularly drinking sugar-free beverages, usually at least once a day. The rest seldom if ever consumed such drinks. While the brain scans were underway, the researchers pumped small amounts of saccharin- or sugar-sweetened water in random order into each recruit’s mouth as the volunteer rated the tastes.

Both the diet soda drinkers and the nondrinkers rated each sweetener about equally pleasant and intense, Green and Murphy report in an upcoming Physiology & Behavior. But which brain regions lit up while making those judgments differed sharply based on who regularly consumed diet drinks.

Certain affected brain regions are associated with offering a pleasurable feedback or reward in response to desirable sensations. And compared with those who don't drink diet soda, the diet soda drinkers “demonstrated more widespread activation to both saccharin and sucrose in reward processing brain regions,” the researchers say.

One of the strongest links seen was diminishing activation of an area known as the caudate head as a recruit’s diet soda consumption climbed. This area is associated with the food motivation and reward system. Green and Murphy also point out that decreased activation of this brain region has been linked with elevated risk of obesity.

When the going gets tough, the tough ought to thank their fathers. New research from Brigham Young University shows that dads are in a unique position to help their adolescent children develop persistence.

BYU professors Laura Padilla-Walker and Randal Day arrived at these findings after following 325 families over several years. And over time, the persistence gained through fathers lead to higher engagement in school and lower rates of delinquency.

"In our research we ask 'Can your child stick with a task? Can they finish a project? Can they make a goal and complete it?'" Day said. "Learning to stick with it sets a foundation for kids to flourish and to cope with the stress and pressures of life."

The scholars from BYU's School of Family Life report their findings June 15 in the Journal of Early Adolescence.

"There are relatively few studies that highlight the unique role of fathers," Padilla-Walker said. "This research also helps to establish that traits such as persistence -- which can be taught -- are key to a child's life success."

What do fireflies, nanorods, and Christmas lights have in common? Someday, consumers may be able to purchase multicolor strings of light that don't need electricity or batteries to glow. Scientists at Syracuse University found a new way to harness the natural light produced by fireflies (called bioluminescence) using nanoscience. Their breakthrough produces a system that is 20 to 30 times more efficient than those produced during previous experiments.

It's all about the size and structure of the custom, quantum nanorods, which are produced in the laboratory by Mathew Maye, assistant professor of chemistry in SU's College of Arts and Sciences; and Rebeka Alam, a chemistry Ph.D. candidate. Maye is also a member of the Syracuse Biomaterials Institute. "Firefly light is one of nature's best examples of bioluminescence," Maye says. "The light is extremely bright and efficient. We've found a new way to harness biology for non-biological applications by manipulating the interface between the biological and non-biological components."

Their work, "Designing Quantum Rods for Optimized Energy Transfer with Firefly Luciferase Enzymes," was published online May 23 in Nano Letters and is forthcoming in print. Collaborating on the research were Professor Bruce Branchini and Danielle Fontaine, both from Connecticut College.

Fireflies produce light through a chemical reaction between luciferin and it's counterpart, the enzyme luciferase. In Maye's laboratory, the enzyme is attached to the nanorod's surface; luciferin, which is added later, serves as the fuel. The energy that is released when the fuel and the enzyme interact is transferred to the nanorods, causing them to glow. The process is called Bioluminescence Resonance Energy Transfer (BRET).

"The trick to increasing the efficiency of the system is to decrease the distance between the enzyme and the surface of the rod and to optimize the rod's architecture," Maye says. "We designed a way to chemically attach, genetically manipulated luciferase enzymes directly to the surface of the nanorod." Maye's collaborators at Connecticut College provided the genetically manipulated luciferase enzyme.

A new approach to drug design, pioneered by a group of researchers at the University of California, San Francisco (UCSF) and Mt. Sinai, New York, promises to help identify future drugs to fight cancer and other diseases that will be more effective and have fewer side effects.

Rather than seeking to find magic bullets -- chemicals that specifically attack one gene or protein involved in one particular part of a disease process -- the new approach looks to find "magic shotguns" by sifting through the known universe of chemicals to find the few special molecules that broadly disrupt the whole diseases process.

"We've always been looking for magic bullets," said Kevan Shokat, PhD, a Howard Hughes Medical Institute Investigator and chair of the Department of Cellular and Molecular Pharmacology at UCSF. "This is a magic shotgun -- it doesn't inhibit one target but a set of targets -- and that gives us a much, much better ability to stop the cancer without causing as many side effects."

Described in the June 7, 2012 issue of the journal Nature, the magic shotgun approach has already yielded two potential drugs, called AD80 and AD81, which in fruit flies were more effective and less toxic than the drug vandetanib, which was approved by the U.S. Food & Drug Administration last year for the treatment of a certain type of thyroid cancer.

Expanding the Targets to Lower a Drug's Toxicity

Drug design is basically all about disruption. In any disease, there are numerous molecular interactions and other processes that take place within specific tissues, and in the broadest sense, most drugs are simply chemicals that interfere with the proteins and genes involved in those processes. The better a drug disrupts key parts of a disease process, the more effective it is.

The toxicity of a drug, on the other hand, refers to how it also disrupts other parts of the body's system. Drugs always fall short of perfection in this sense, and all pharmaceuticals have some level of toxicity due to unwanted interactions the drugs have with other molecules in the body.

Scientists use something called the therapeutic index (the ratio of effective dose to toxic dose) as a way of defining how severe the side effects of a given drug would be. Many of the safest drugs on the market have therapeutic indexes that are 20 or higher -- meaning that you would have to take 20 times the prescribed dose to suffer severe side effects.

Many cancer drugs, on the other hand, have a therapeutic index of 1. In other words, the amount of the drug you need to take to treat the cancer is the exact amount that causes severe side effects. The problem, said Shokat, comes down to the fact that cancer drug targets are so similar to normal human proteins that the drugs have widespread effects felt far outside the tumor.

Physicists Predict Success of Movies at the Box Office Based Solely On Advertising Costs

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A group of Japanese scientists have surprised themselves by being able to predict the success or failure of blockbuster movies at the box office using a set of mathematical models.

The researchers, publishing their study June 15, in the Institute of Physics and German Physical Society's New Journal of Physics, used the effects of advertising and word-of-mouth communication to create a model that turned out to be successful in predicting how each movie fared once it hit the silver screen.

The only data the researchers needed to put into the model were the daily advertisement costs of 25 movies that appeared in Japanese cinemas.

Their model was originally designed to predict how word-of-mouth communication spread over social networks, applying it to conversations about movies in particular, which was a success; however, they also found that when they overlapped their predictions with the actual revenue of the films, they were very similar.

They now intend to apply their model to other commercial markets, such as online music, food snacks, noodle cups, soft drinks and local events.

The researchers, from Tottori University, used their model to calculate the likelihood of an individual going to watch a movie in a Japanese cinema over a period ranging from 60 days prior to the movie's opening date to 100 days after it had opened.

Recognising that word-of-mouth communication, as well as advertising, has a profound effect on whether a person goes to see a movie or not, whether this is talking about it to friends (direct communication) or overhearing a conversation about it in a café (indirect communication), the researchers accounted for this in their calculations.

Tiny microbes are at the heart of a novel agricultural technique to manage harmful greenhouse gas emissions. Scientists have discovered how microbes can be used to turn carbon dioxide emissions into soil-enriching limestone, with the help of a type of tree that thrives in tropical areas, such as West Africa.

Researchers have found that when the Iroko tree is grown in dry, acidic soil and treated with a combination of natural fungus and bacteria, not only does the tree flourish, it also produces the mineral limestone in the soil around its roots.

The Iroko tree makes a mineral by combining calcium from Earth with CO2 from the atmosphere. The bacteria then create the conditions under which this mineral turns into limestone. The discovery offers a novel way to lock carbon into the soil, keeping it out of the atmosphere.

In addition to storing carbon in the trees' leaves and in the form of limestone, the mineral in the soil makes it more suitable for agriculture.

The discovery could lead to reforestation projects in tropical countries, and help reduce carbon dioxide emissions in the developing world. It has already been used in West Africa and is being tested in Bolivia, Haiti and India.

The findings were made in a three-year project involving researchers from the Universities of Edinburgh, Granada, Lausanne and Neuchatel, Delft University of Technology, and commercial partner Biomim-Greenloop. The project examined several microbiological methods for locking up CO2 as limestone, and the Iroko-bacteria pathway showed best results. Work was funded by the European Commission under the Future & Emerging Technologies (FET) scheme.

Energy efficiency is the most significant challenge standing in the way of continued miniaturization of electronic systems, and miniaturization is the principal driver of the semiconductor industry. "As we approach the ultimate limits of Moore's Law, however, silicon will have to be replaced in order to miniaturize further," said Jeffrey Bokor, deputy director for science at the Molecular Foundry at the Lawrence Berkeley National Laboratory and Professor at UC-Berkeley.

To this end, carbon nanotubes (CNTs) are a significant departure from traditional silicon technologies and a very promising path to solving the challenge of energy efficiency. CNTs are cylindrical nanostructures of carbon with exceptional electrical, thermal and mechanical properties. Nanotube circuits could provide a ten-times improvement in energy efficiency over silicon.

Early promise

When the first rudimentary nanotube transistors were demonstrated in 1998, researchers imagined a new age of highly efficient, advanced computing electronics. That promise, however, is yet to be realized due to substantial material imperfections inherent to nanotubes that left engineers wondering whether CNTs would ever prove viable.

Over the last few years, a team of Stanford engineering professors, doctoral students, undergraduates, and high-school interns, led by Professors Subhasish Mitra and H.-S. Philip Wong, took on the challenge and has produced a series of breakthroughs that represent the most advanced computing and storage elements yet created using CNTs.

These high-quality, robust nanotube circuits are immune to the stubborn and crippling material flaws that have stumped researchers for over a decade, a difficult hurdle that has prevented the wider adoption of nanotube circuits in industry. The advance represents a major milestone toward Very-large Scale Integrated (VLSI) systems based on nanotubes.

"The first CNTs wowed the research community with their exceptional electrical, thermal and mechanical properties over a decade ago, but this recent work at Stanford has provided the first glimpse of their viability to complement silicon CMOS transistors," said Larry Pileggi, Tanoto Professor of Electrical and Computer Engineering at Carnegie Mellon University and director of the Focus Center Research Program Center for Circuit and System Solutions.

Major barriers

While there have been significant accomplishments in CNT circuits over the years, they have come mostly at the single-nanotube level. At least two major barriers remain before CNTs can be harnessed into technologies of practical impact: First, "perfect" alignment of nanotubes has proved all but impossible to achieve, introducing detrimental stray conducting paths and faulty functionality into the circuits; second, the presence of metallic CNTs (as opposed to more desirable semiconducting CNTs) in the circuits leads to short circuits, excessive power leakage and susceptibility to noise. No CNT synthesis technique has yet produced exclusively semiconducting nanotubes.

"Carbon nanotube transistors are attractive for many reasons as a basis for dense, energy efficient integrated circuits in the future. But, being borne out of chemistry, they come with unique challenges as we try to adapt them into microelectronics for the first time. Chief among them is variability in their placement and their electrical properties. The Stanford work, that looks at designing circuits taking into consideration such variability, is therefore an extremely important step in the right direction," Supratik Guha, Director of the Physical Sciences Department at the IBM Thomas J. Watson Research Center .

"This is very interesting and creative work. While there are many difficult challenges ahead, the work of Wong and Mitra makes good progress at solving some of these challenges," added Bokor.

Realizing that better processes alone will never overcome these imperfections, the Stanford engineers managed to circumvent the barriers using a unique imperfection-immune design paradigm to produce the first-ever full-wafer-scale digital logic structures that are unaffected by misaligned and mis-positioned CNTs. Additionally, they addressed the challenges of metallic CNTs with the invention of a technique to remove these undesirable elements from their circuits.

Visual and auditory stimuli that elicit high levels of engagement and emotional response can be linked to reliable patterns of brain activity, a team of researchers from The City College of New York and Columbia University reports. Their findings could lead to new ways for producers of films, television programs and commercials to predict what kinds of scenes their audiences will respond to.

"Peak correlations of neural activity across viewings can occur in remarkable correspondence with arousing moments of the film," the researchers said in an article published in the journal Frontiers in Human Neuroscience. "Moreover, a significant reduction in neural correlation occurs upon a second viewing of the film or when the narrative is disrupted by presenting its scenes scrambled in time."

The researchers used EEG (electroencephalography), which measures electrical activity across the scalp, to collect data on brainwaves of 20 human subjects, who were shown scenes from three films with repeat viewings. Two films, Alfred Hitchcock's "Bang! You're Dead" and Sergio Leone's "The Good, the Bad and the Ugly," contained moments of high drama expected to trigger responses. The third, an amateur film of people walking on a college campus, was used as a control.

"We found moments of high correlation (between brainwave activity during separate viewings) and moments when this did not occur," said Dr. Lucas C. Parra, Herbert G. Kayser Professor of Biomedical Engineering in CCNY's Grove School of Engineering, and a corresponding author. "By looking at patterns of oscillation we could tell at which moments a person was particularly engaged. Additionally, we could see whether the correlation occurred across subjects and repeated viewings."

Measurements along the EEG alpha activity scale show the degree of attentiveness in a person, he explained. When the oscillations are strong, a person is relaxed, i.e. not engaged. When a person is very attentive, alpha activity is low.

Peaks in engagement were correlated to three kinds of scenes, said Dr. Jasek Dmochowski, a post-doctoral fellow in the Grove School and a corresponding author. They included moments with powerful visual cues, such as a close-up on the gun in "Bang! You're Dead," scenes with ominous music in which the visual component was not significant, and meaningful scene changes.

The researchers found significantly less neural correlation on participants' second viewings and when scenes were scrambled and shown out of sequence. "Following a narrative is complex and involves a lot of distributed processing. When a person doesn't have a sense of the narrative there is much less correlation (across views of the same or another subject)," Dr. Dmochowski said.

Having demonstrated the correlations between intense stimuli and brainwave reliability, the research team now wants to locate where in the brain the response occurs, Professor Parra said. He wants to deploy a combination of EEG and magnetic resonance imaging to "get the best of both worlds:" the fine temporal resolution of EEG and the detailed imagery of MRI.

The team sees several potential applications for the ability to quantify levels of engagement, including neuro-marketing, quantitative assessment of entertainment, measuring the impact of narrative discourse and the study of attention deficit disorders. "Advertisers would love to know where and when an ad is engaging," he noted.

UN talks on sustainable development are encountering disputes, delays and diplomatic wrangling, days before world leaders arrive to sign a new agreement.

The talks, in Rio de Janeiro, are aimed at putting the world economy on a more sustainable path, helping people out of poverty while protecting nature.

Yet developing countries have walked out over money, and the presence of Palestinians has brought complications.

Campaigners say there is little hope of momentous changes being agreed here.

"That's not even a question anymore," said Lasse Gustavsson, executive director of conservation with WWF International.

"It's clear we will get something, but it's equally clear we will not get what the planet needs," he told BBC News.

Preparatory talks broke down on Thursday evening as the G77/China bloc of 131 developing countries walked out of a number of sessions.

They said they could not talk about issues such as the green economy - which some see as likely to put a brake on development - unless western nations were clear about the amount of financial aid they were prepared to pledge.

The draft agreement negotiators are working on contains paragraphs that would commit the developed world to providing either $30bn per year or $100bn per year - but western governments are not prepared to agree to either figure.

Long weekend

Discussion groups reconvened on Friday morning; and Nikhil Seth, head of the Rio+20 secretariat, told reporters there was a "sense of cautious optimism and constructive engagement".

Scientists working on Voyager 1 are receiving further data suggesting the probe is close to crossing into interstellar space.

The Nasa mission, which launched from Earth in 1977, could leave our Solar System at any time.

It is now detecting a sharp rise in the number of high-energy particles hitting it from distant exploded stars.

The observation was predicted, and is another indication that Voyager will soon reach its historic goal.

"The laws of physics say that someday Voyager will become the first human-made object to enter interstellar space, but we still do not know exactly when that someday will be," Ed Stone, the Voyager project scientist at the California Institute of Technology in Pasadena, said in a Nasa statement.

"The latest data indicate that we are clearly in a new region where things are changing more quickly. It is very exciting. We are approaching the Solar System's frontier."

Voyager 1 is travelling at about 17 km per second (38,000 mph), and is almost 18 billion km (11 billion miles) from Earth.

The vast separation means a signal from the probe takes more than 16 and a half hours to arrive at Nasa's receiving network.

In the last three years, Voyager has seen a steady increase in the number of cosmic rays entering its two high-energy telescopes, but in the past month the counts have jumped markedly.

Mexican President Felipe Calderon says he is cancelling the construction of a huge tourist resort in Baja California over concerns it could damage a nearby marine reserve.

Mr Calderon said he had withdrawn the permits from the Spanish developers.

He said developers Hansa Baja had not been able to prove the planned resort would not harm the environment.

Activists said it would have damaged the Cabo Pulmo coral reef and park, a haven for marine life.

Speaking from his official residence, President Calderon said that "because of its size we have to be absolutely certain that it wouldn't cause irreversible damage, and that absolute certainty simply hasn't been proved".

Environmental battle

Mexican authorities had granted Hansa Baja initial permits to build about 30,000 hotel rooms, two golf courses and a marina near the tip of Baja California.

The 9,400-acre (3,800-hectare) project, called Cabo Cortes, caused concern among many locals and environmental groups.

The activists said it would threaten Cabo Pulmo National Marine Park, which has some of the best preserved coral reef in Mexico's Pacific region.

The park is home to more than 200 fish species and was designated a Unesco World Heritage Site in 2005.

Environmentalists, who had protested against the development for years, welcomed Mr Calderon's announcement.

GM crops that make their own insecticide also deliver benefits for their conventional plant neighbours, a study in China has concluded.

These strains seem to boost populations of natural pest-controlling predators, and this effect spills over to non-transgenic crops, the research found.

Details of the work by a Chinese-French team appear in the journal Nature.

But one group critical of GM planting described the effect as a spillover "problem", not a "benefit".

Scientists investigated a modified version of cotton grown in China that generates a bacterial insecticide.

The strain has led to a reduction in the use of insecticide to control a major pest, the cotton bollworm.

After the GM cotton was introduced, researchers saw a marked increase in numbers of pest predators such as ladybirds, lacewings and spiders.

At the same time, populations of crop-damaging aphids fell.

The predatory insects also controlled pests in neighbouring fields of non-GM maize, soybean and peanut crops, said the team led by Dr Kongming Wu from the Chinese Academy of Agricultural Sciences in Beijing.

Commenting on the study, Professor Guy Poppy from the University of Southampton, UK, said: "Global food security will require us to sustainably intensify agriculture. Opponents of GM have argued this can't be done through biotechnology, whereas this research challenges this view and demonstrates the wider benefits of using GM plants.

"By reducing the need for insecticides against caterpillars, insect biodiversity is increased and this is shown to have added benefits outside of the GM crop field."

Emma Hockridge, head of policy at the Soil Association, the British campaign group that advocates organic farming, said: "Encouraging predator insects is crucial to managing crop pests sustainably - indeed, that's how organic farmers avoid pesticides, using natural processes to encourage beneficial predators.

"This study finds that Bt cotton is a better habitat for such predators than cotton that has been sprayed with pesticides.

Little has been done to protect marine life since the 1992 Rio Earth Summit, conservation scientists conclude.

On pledges to protect key habitat and restrict the size of fishing fleets, they say progress has been "pitiful".

Their analysis is carried in the journal Science and is being discussed during final preparations for the Rio+20 summit, which opens next week.

Conservationists were delighted by Australia's move to set up the world's largest network of marine reserves.

But globally, the picture is bleak, they say.

"Our analysis shows that almost every commitment made by governments to protect the oceans has not been achieved," said Jonathan Baillie, director of conservation at the Zoological Society of London (ZSL).

"If these international processes are to be taken seriously, governments must be held accountable and any future commitments must come with clear plans for implementation and a process to evaluate success or failure."

The rise of inflammatory bowel diseases could be down to our shifting diets causing a "boom in bad bacteria", according to US researchers.

Mouse experiments detailed in the journal Nature linked certain fats, bacteria in the gut and the onset of inflammatory diseases.

The researchers said the high-fat diet changed the way food was digested and encouraged harmful bacteria.

Microbiologists said modifying gut bacteria might treat the disease.

Inflammatory bowel diseases (IBDs), such as Crohn's and ulcerative colitis, affect one in every 350 people in the UK. When the gut becomes inflamed it can lead to abdominal pain and diarrhoea.

The researchers at the University of Chicago said the incidence of the diseases was increasing rapidly.

They used genetically modified mice which were more likely to develop IBDs. One in three developed colitis when fed either low-fat diets or meals high in polyunsaturated fats. This jumped to nearly two in three in those fed a diet high in saturated milk fats, which are in many processed foods.

Earth observation programme even though the long-term budget to support it has still not been agreed.

The European Space Agency has taken a decision this week to reserve a rocket to launch the Sentinel-1 radar satellite in 2013.

It should be followed into orbit by further satellites in 2014.

But the European Union, which owns the programme and will fund its operation, has stalled on the financing.

It means - at the moment - that Sentinel-1 would get into space with only a few months of guaranteed budget to sustain its observations of the planet.

Nonetheless, the council of Esa, which has been meeting in Paris over the past two days, is confident the money issues can soon be resolved.

"The council has asked the executive to go ahead, to start all the activities that will make a launch possible next year, between October and the end of 2013," explained European Space Agency (Esa) spokesman Franco Bonacina.

"We cannot wait; if we wait, we risk losing our launch slot and that could end up costing us more money," he told BBC News.Failed observer

Sentinel-1 would ride into orbit on a Soyuz rocket from the Sinnamary spaceport in French Guiana. The spaceport's operator, Arianespace, needs a year's notice that a satellite will be ready to fly so that it can plan a launch schedule.

Without a reservation being made now, Sentinel-1's flight would almost certainly be bumped to 2014.

Irked me... They're missing the point. Cancer has already been cured... More than once. Different ways. And always ignored because it's not patentable... (I've probably done too much reading on the topic.) For a great site on cancer, see:

Bottom line is, 'alternative' in this context is simply another word for 'unproven'. Conventional treatments have been rigourously tested and proven in double-blind, peer-reviewed clinical trials. No alternative medicine has been proven in this way - if it had, it would no longer be alternative medicine, it would just be medicine.

Right... And when you actually look at the evidence for these "rigourously tested and proven in double-blind, peer-reviewed clinical trial" methods, i.e. chemo, you find that you stand a better chance of survival and having your cancer cured by NOT taking chemo. Like seriously... WTF?!?

The cancer industry is a complete scam. They're criminally irresponsible. One need only look at Burzynski's results and compare them to chemo. Here's a documentary on the topic:

As for the grape diet, well, just sounds like a bunch of nonsense.

To be certain, there are a lot of quacks out there. But you find most of them in the oncology departments...

People that do not drink diet soda on a regular basis generally do not like diet soda and think it tastes funny, so it would be reasonable to assume that the pleasure from the sweetness would be differently displayed.

I wonder what the results would be for long time heavy drinkers of diet sodas, that prefers the artificial sweetners and actually think real sugar tastes awful (yes, we do exist). Would sugar light up the same parts of the brain as it would in normal people? Would it light up the parts of the brain associated with bad tastes or unpleasurable experiences?

About the grasshoppers' terror...

Sounds like a survival thing, beneficial to the grasshoppers. If there are predators present, it's not a good environment for survival. By causing less vegetation to grow, they make it an even less hospitable environment for their species, driving them to find greener pastures where there would be not only more vegetation, but less predators, as well.

The study on the success of movies based on advertising costs...

The first rule of advertising states:

He who has a thing to sellwho goes and whispers in a wellIs not apt to get the dollarsas he who climbs the hill and hollers.

It would be reasonable to assume that if he can afford a megaphone, he'll sell even more...and if he can hire more people with megaphones to climb up on other hills, even more.

We could probably repeat the study with similar results here in the US, but based on politicians and the money raised and spent to finance their campaigns, and the election results that follow. This is what all the noise over corporations being able to funnel unlimited amounts of money into campaign funds is all about, essentially allowing corporations to buy elections. The politician with the largest purse, generally wins, and corporations are in a better position to finance political campaigns than private citizens are, very much the same way the big movie studios can buy more viewers than a small indy company can, based solely on the cash available to spend on advertising.

About the milk fats...

There is a good reason why lactose intolerance in most species of adult mammals is the norm.

Visual and auditory stimuli that elicit high levels of engagement and emotional response can be linked to reliable patterns of brain activity, a team of researchers from The City College of New York and Columbia University reports. Their findings could lead to new ways for producers of films, television programs and commercials to predict what kinds of scenes their audiences will respond to.

Right. Because righting a good story is just to hard (to mass produce...). Whats next a photo/sound/light sequence that will cause anyone with a pulse to orgasm for 20min straight?? Christ...If they'ed quit trying to short-stroke human emotions maybe the population wouldn't be so screwed up half the time.